1. Field of the Invention
This invention relates generally to telephone systems and more particularly to message transfer circuits for allowing an attendant set to transfer a message to a selected principal set.
2. Description of the Prior Art
Telephone answering systems which enable a centrally located telephone operator to monitor the calls received by a plurality of subscriber telephones are in widespread use. Early telephone answering systems required that the subscriber contact the operator, normally by telephone, to find out if anyone had called while he was away and left a message. Progress in the telephone art has resulted in the development of circuits which enable the operator to answer a call directed to a principal set and leave a message at that principal set in the form of a visual signal, e.g., lamp, informing a subscriber that a message is waiting at the operator's location. In the past such message waiting circuits have required the use of a separate message circuit between each subscriber's set and the operator's set. Each such message circuit required the actuation of an associated message key or switch at the operator's location to energize the message lamp at the subscriber's set. Thus, a separate message key was required at the operator's location for each subscriber's set. The present invention provides an improvement over the prior art message waiting signal transfer circuitry in terms of cost, complexity and a reduction in the time required of the central operator.